Officials are probing how a 51-year-old highway bridge came to collapse in the Italian port city of Genoa yesterday, killing at least 26 people and injuring 16 others as it sent dozens of vehicles tumbling into a heap of concrete and twisted steel.

Republican presidential hopeful Donald Trump has labelled the reigning Miss Universe a "hypocrite" after she spoke out against his characterisation of Mexican immigrants as "rapists".

The current Miss Universe, Paulina Vega, described Mr Trump's highly inflammatory comments, made in the past fortnight, as "hurtful and unfair" – but Trump countered by suggesting the Colombian stunner should relinquish her title.

"Miss Universe, Pauline Vega, criticized me for telling the truth about illegal immigration, but then said she would keep the crown. Hypocrite," he tweeted over the weekend.

Apparently subscribing to the adage that there is no bad publicity, Trump infuriated all and sundry with his immigration comments, prompting NBC – which jointly owns the rights to the Miss Universe and Miss America pageants with Trump – to cut ties with the billionaire.

'Hurtful and unfair'...Miss Universe, Paulina Vega. (AAP) ()

"At NBC, respect and dignity for all people are cornerstones of our values," the company said last week.

"Due to the recent derogatory statements by Donald Trump regarding immigrants, NBCUniversal is ending its business relationship with Mr Trump."

Mr Trump also fell foul of Neil Young recently after the veteran rocker slammed the use of the classic track "Rockin' in the Free World" at a campaign event; old Shakey told Trump not to use the tune again, and summarily endorsed Democratic contender Bernie Sanders.